History and Impact of Additive Manufacturing

History and Impact of Additive Manufacturing In the recent years, technology has been evolving at an exponential rate, due to important breakthroughs in research and development of new ways to produce efficient materials and structures. One of the most important technological step forward was the implementation of the extended use of Additive Manufacturing Machines, also known as 3D Printers. This revolutionary concept of Additive Manufacturing (AM) describes the technologies that build 3D objects by adding layer-upon-layer of material, whether the material is plastic, metal, concrete or maybe one dayà ¢Ã¢â€š ¬Ã‚ ¦. human tissue? The history of AM Manufacturing: The first additive manufacturing equipment and materials were developed by Charles Hull in the early 1980s, and he called the process stereolithography, (Jane Bird 2012). Hull, who has a bachelors degree in engineering physics, was working on making plastic objects from photopolymers at the company Ultra Violet Products in California. Stereolithography uses an .stl file format to interpret the data in a CAD file, allowing these instructions to be communicated electronically to the 3D printer. Along with shape, the instructions in the .stl file may also include information such as the color, texture, and thickness of the object to be printed.( Gross BC, Erkal JL, Lockwood SY, Chen C, Spence DM -2014) By the early 2010s, the terms 3D printing and additive manufacturing evolved senses in which they were alternate umbrella terms for AM technologies, one being used in popular vernacular by consumer maker communities and the media, and the other used officially by industrial AM end use p art producers, AM machine manufacturers, and global technical standards organizations.(Ishengoma, Fredrick R.; Mtaho, Adam B.-2014) Many other companies have since developed 3D printers for commercial applications. Hulls work, as well as advances made by other researchers, has revolutionized manufacturing, and is poised to do the same in many other fields-including medicine. (Gross BC, Erkal JL, Lockwood SY, Chen C, Spence DM -2014) 2. The types of AM Processes Although the term 3D Printing is used as a synonym for all Additive Manufacturing processes, there are actually lots of individual processes which vary in their method of layer manufacturing. Individual processes will differ depending on the material and machine technology used. Hence, in 2010, the American Society for Testing and Materials (ASTM) group ASTM F42 Additive Manufacturing, formulated a set of standards that classify the range of Additive Manufacturing processes into 7 categories (Standard Terminology for Additive Manufacturing Technologies -2012). These categories are: VAT Photopolymerisation which refers to using a vat of liquid photopolymer resin, out of which the model is constructed layer by layer; Material Jetting, which is used to create objects in a similar method to a two-dimensional ink jet printer. Material is jetted onto a build platform using either a continuous or Drop on Demand approach; Binder Jetting, which uses two materials; a powder based material and a binder. The binder is usually in liquid form and the build material in powder form. A print head moves horizontally along the x and y axes of the machine and deposits alternating layers of the build material and the binding material. Material Extrusion; Fuse deposition modelling is a common material extrusion process. Material is drawn through a nozzle, where it is heated and is then deposited layer by layer. The nozzle can move horizontally and a platform moves up and down vertically after each new layer is deposited. Inkjet Printing is a noncontact technique that uses thermal, electromagnetic, or piezoelectric technology to deposit tiny droplets of ink (actual ink or other materials) onto a substrate according to digital instructions. Sheet Lamination processes that include ultrasonic additive manufacturing and laminated object manufacturing. Directed Energy Deposition which covers a range of terminology: Laser engineered net shaping, directed light fabrication, direct metal de position, 3D laser cladding It is a more complex printing process commonly used to repair or add additional material to existing components. 3. Description of the way Thermal Inkjet Printing AM Machines work As mentioned above, TIJ printers use a technique that uses thermal, electromagnetic, or piezoelectric technology to deposit tiny droplets of ink (actual ink or other materials) onto a substrate according to digital instructions. In inkjet printing, droplet deposition is usually done by using heat or mechanical compression to eject the ink drops. In TIJ printers, heating the print head creates small air bubbles that collapse, creating pressure pulses that eject ink drops from nozzles in volumes as small as 10 to 150 picolitres. Droplet size can be varied by adjusting the applied temperature gradient, pulse frequency, and ink viscosity. TIJ printers are particularly promising for use in tissue engineering and regenerative medicine. Because of their digital precision, control, versatility, and benign effect on mammalian cells, this technology is already being applied to print simple 2D and 3D tissues and organs (also known as bioprinting). (Cui X, Boland T, DLima DD, Lotz MK -2012) 4. The benefits of AM Machines in Medical Industry The strengths of Additive Manufacturing lie in those areas where conventional manufacturing reaches its limitations. The technology is of interest where a new approach to design and manufacturing is required so as to come up with solutions to complex and complicated situations. It enables a design-driven manufacturing process where design determines production and not the other way around. What is more, AM allows for highly complex structures which can still be extremely light and stable, which is a particularly important characteristic for medical bio-engineering. It provides a high degree of design freedom, the optimization and integration of functional features, the manufacture of small batch sizes at reasonable unit costs and a high degree of product customization even in serial production, thus providing the possibility of adapting every AM designed apparatus to every patient needs. (S.V Murphy, A. Atala -2014) For example, 3D printing has been considered as a method of implant ing stem cells capable of generating new tissues and organs in living humans. With their ability to transform into any other kind of cell in the human body, stem cells offer huge potential in 3D bio-printing. (3D Masterminds 7 Ways 3D Printing Is Disrupting the Medical Industry-2015) Many medical devices, such as hearing aids, dental crowns, and surgical implants are relatively small in size and therefore suitable for the production available through common AM systems. According to a new research report from Albany, NY based Transparency Market Research, the global market for 3D printing in medical application was valued $354.5 million in 2012 and is expected to grow at a compound annual growth rate (CAGR) of 15.4 percent from 2013 to 2019 to reach $965.5 million by 2019. (Wohlers Associates 2014) 5. Conclusion 3D printing has become a useful and potentially transformative tool in a number of different fields, including medicine. As printer performance, resolution, and available materials have increased, so have the applications. Researchers continue to improve existing medical applications that use 3D printing technology and to explore new ones. The medical advances that have been made using 3D printing are already significant and exciting, but some of the more revolutionary applications, such as organ printing, will need time to evolve, but still, taking into account the way technology evolves today, this kind of application may soon be accessible. 6. References -Jane Bird (2012-08-08). Exploring the 3D printing opportunity. The Financial Times.  Ãƒâ€šÃ‚   https://www.ft.com/content/6dc11070-d763-11e1-a378-00144feabdc0#axzz24gFn5Cal/ Gross BC, Erkal JL, Lockwood SY, et al. Evaluation of 3D printing and its potential impact on biotechnology and the chemical sciences. Anal Chem. 2014;86(7):3240-3253 https://all3dp.com/types-of-3d-printer-technology-explained/ -Ishengoma, Fredrick R.; Mtaho, Adam B. (2014-10-18). 3D Printing: Developing Countries Perspectives. International Journal of Computer Applications. 104 (11): 30-34. arXiv:1410.5349Freely accessible. doi:10.5120/18249-9329. ISSN 0975-8887. -Cui X, Boland T, DLima DD, Lotz MK Recent Pat Drug Deliv Formul. 2012 Aug; 6(2):149-55. -3D bioprinting of tissues and organs Sean V Murphy Anthony Atala  © 2014 Nature America -3D Masterminds 7 Ways 3D Printing Is Disrupting the Medical Industry-2015: http://3dmasterminds.com/7-ways-3d-printing-is-disrupting-the-medical-industry/ Wohlers Associates Report 2014 https://wohlersassociates.com/2014report.htm

Thomas Jefferson Essays -- essays research papers

Thomas Jefferson is remembered in history not only for the offices he held, but also for his belief in the natural rights of man as expressed in the Declaration of Independence and his faith in the people’s ability to govern themselves. Through his political career, Thomas Jefferson advocated democratic principles and adhered to his liberal ideology. However, as a president he found it difficult to maintain these policies in the noisy arena of politics. Consequently, circumstances forced him to reverse himself in some degree on these concepts. When he was voted into the presidency, Jefferson devoted a major section of his inaugural address to the "’the essential principles of our government, and consequently those which ought to shape it’s administration’" (Cunningham). Here he reiterated his basic political principles and the leading policies that he had professed as a candidate, which he now restated as the guiding pillars of his administration. He began by affirming "’equal and exact justice to all his men, of whatever state or persuasion, religious or political.’" Next, Jefferson proclaimed, "Peace, commerce, and honest friendship with all nations, entangling alliances with none." He then went on to affirm his commitment to the rights of the states and the preservation of the central government. Continuing to intermingle general principles and specific policies, that new president declared that he favored reliance for defense on a "militia rather than an army, a small navy" (Cunningham) and prosperity through "economy, the payment of debts, and the encouragement of agriculture and commerce as its handmaid." He also emphasized basic rights such as freedom of speech, freedom of the press, and impartially selected juries. "These principles," Jefferson concluded, "form the brightest constellation, which has gone before us and guided our steps through an age of revolution and reformation†¦ They should be the creed of our political faith, the text of civic instruction, the touchstone by which we try the services of those we trust." Unfortunately for Jefferson, marinating this creed would not be easy during this period of history. Jefferson maintained his governing principles throughout the most part of his presidency.... ...elpless American ship was thereupon forced to surrender four of its men. One was a British deserter, but three were Americans. Many Americans wanted to go to war against Britain over this incident. However, Jefferson was determined to avoid war, feeling he could bring Britain to terms by applying economic pressure. In December 1807, the Congress passed the Embargo Act. American ships were forbidden to sail from American ports to any European port. Jefferson believed that England and France could not survive without American trade. However, he had greatly underestimated the effect of the embargo on the United States itself. All parts of the country were affected, especially the industrial and commercial North. In order to avoid war, Jefferson was forced to act against two of his principles by risking American commerce and terminating friendly relationships with other nations. Despite the unavoidable circumstances that caused his actions, Jefferson still proved to be one of the most valued presidents. His ideas, firmly established in the Declaration of Independence, are the foundation of modern society. Current politicians and citizens value many of his principles as well.

Personal Computers Essay

Background. The Personal Computers at their advent were simple machines with less number of parts and limited capabilities. Less power was required to operate the computers and computer heating was never a major problem. However with the development in microprocessor and solid state technologies there was a revolution in how people used computers. The computers today can be configured according to ones needs and many add on components like graphics cards, Modems, USB devices etc. can be fitted on computers . Motherboards today also come with an increased number of components. However with the increase in components a new problem of heating has surfaced in computers. Problems and Motivation Although these components have increased the functionality of computers tremendously it has raised a serious problem of heating. With the increase in number of components the demand for power supply has increased. The components consume more energy and generate large amount heat. Electronic devices perform inefficiently or even get damaged as a result of excessive heat. Hence new challenges to protect these components from getting damaged by proper cooling of heat has emerged. Though the components have increased in numbers the size of PCs has kept reducing. People today prefer smaller PCs for space constraints and aesthetics. In order to keep in line with the reducing sizes the Power supply and the cooling system should also go transformation in sizes. One needs to design cooling systems with greater performances yet at a reduced scale. As the power supply and cooling are the components of PC case there is a need to renovate these cases to protect computer components from getting overheated and damaged. At the same time the it should be scaled down and match the aesthetics of other parts such as monitors, keyboards etc which come in designer shapes today. Research Aims and Objectives With reference to the above discussed problem there is a need to develop PC cases which are responsible for computer cooling. The aim of the project is to create simulation in order to find a better solution over the existing PC Cases and prevent spreading of heat to other components. The project will achieve three main objectives The initial objective would be to understand the principle of fluid dynamics and apply it to the PC Case problem. Secondly we will design a model to convert humid air by applying Computational Fluid Dynamics (CFD) The final objective would be to provide recommendations for the PC Case. Literature Review The preliminary literature was done on the existing problems in PC Cases and the sources of heat in computer system . The current methodologies implemented for cooling were also studied. Basic literature on application of fluid dynamics and use of Computational Fluid Dynamics to solve problems was also reviewed Methodology The Research will be experimental in nature. simulation model of the existing PC Cases will be developed in CFD. The models will be simulated again with modification for the proposed air cooling. The comparison between the two simulation will help in developing the cooling system and designing of the PC Cases. The results obtained will be experimental in nature and the problem is achievable theoretically with the help of CFD. As the project intends to suggest changes over the existing models the use of Simulation is justified to obtain outcomes as the existing systems are already simulated for cooling by making use of CFD. Triangulation: Mathematical models for the fluid dynamics of air can be constructed and solved for various conditions and the outcomes of these can be cross examined with the that of computer simulations. An experimental set-up can be created to check the prototype of cooling system and the results can be compared. Reliability : The prototype and the simulated models can be tested over a number of systems/components from different manufacturers and checked for reliability. Ethics: The project will adhere to all the guidelines and protocols of electronic manufacturing devices in terms of manufacturing, quality and safety. Environment : The proposed PC cases will be environment friendly. It may be manufactured from environmental friendly recycled materials to reducing global warming. Noise reduction will be achieved considerably with the improved change in design. Analysis The outcomes of the project will help in analyzing the reduction achieved in heat generated and the prevention of components. It will also analyze the cost of implementation and its economic feasibility. Conclusion With correct implementation of fluid dynamics modification in the existing PC cases can be achieved to cool heat efficiently and prevent components from overheating. Although the project is experimental in nature and relies mainly on simulation there may be a variation in its actual implementations. Whether the PC Cases behave as recommended can only be judged only by their practical application the project can be a strong foundation to extend this future scope.

Doctrine of Foreign Policy Constructed by U.S. Presidents

There were many presidents of the United States that were able to construct doctrines during their presidency terms in office that defined their individual foreign policy goals and/or aims. Just to name a few there was the Monroe Doctrine of 1823, Truman Doctrine 1947 and the Reagan Doctrine of 1984. For example, the Monroe Doctrine was constructed for two main reasons: 1) John Adams, Secretary of State, suggested the principle that the Western hemisphere was not an option for any further colonization by the European powers and 2) the U.S. would defend the freedom of other nations. The Monroe Doctrine proved its power in the 1900’s when President Roosevelt enforced the doctrine during the Venezuela Border Dispute as well as securing the independence of Cuba from the abusive Spanish rule. During his Presidency, The Ronald Reagan Doctrine was a foreign policy in the United States from 1980 to 1991. The doctrine was to help eliminate communist governments such as Latin America, Africa and Asia which were supported by the Soviet Union (Lagon, 1994). The plan was to implement support to private and open guerilla and resistance movements that were supported by the Soviet in communist countries. Containment was the official policy towards communism and in creating the Reagan Doctrine, the focus started from keeping communism from spreading then it shifted to eliminating existing communist governments. In addition to the eliminations of the communist governments, the UnitedShow MoreRelatedEssay on Presidency of Theodore Roosevelt835 Words   |  4 PagesAfter the assassination of President McKinley, Theodore Roosevelt inherited a growing empire when he took office in 1901. The U.S. had annexed Hawaii in 1898 and Spanish-American War granted the U.S. control of the Phili ppines. It also led the U.S. to establish a protectorate over Cuba and grant territorial status for Puerto Rico. 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